The present invention relates to an energy control system, and more particularly, to a system for controlling the air flow produced from a central forced air apparatus to rooms occupied by human beings, as detected by occupancy sensors.
Concern with energy consumption in heating or cooling a building or a dwelling has caused a number of systems to control the energy usage to be proposed. In U.S. Pat. No. 3,814,173, a forced air heating/cooling system has a plurality of room thermostats which open or close the air dampers. The thermostats are interrogated to determine the demand for the heated or cooled air. The fan speed of the heating/cooling unit is then adjusted in accordance to the demand. U.S. Pat. No. 3,865,181 also discloses a system wherein the air supply rate is controlled.
U.S. Pat. No. 3,882,928 and U.S. Pat. No. 3,724,534 both disclose heating or cooling of a dwelling by zones. Portions of the building are heated or cooled depending on the time of the day. Thus, in the daytime, the zone which is heated or cooled would be the living areas; whereas, in the nighttime, the zone of heating or cooling would be the sleeping quarters.
In U.S. Pat. No. 4,174,064 and U.S. Pat. No. 3,934,797, both disclose energy conserving systems based upon the condition of occupancy of the rooms. However, the condition of occupancy is a priori known; i.e., either by check-out status as in U.S. Pat. No. 4,174,064 or is clock cntrolled as in U.S. Pat. No. 3,934,797. In addition, both patents disclose two states of temperature control in each room: one range of temperature control for occupied status, with another range of temperature control for unoccupied status.
Computer control of the environment in a building is known. See, for example, U.S. Pat. No. 3,896,871. Infrared intrusion devices to detect the presence of an intruder within a region are also known. See, for example, U.S. Pat. No. 4,179,691.